Mining machine



y 1943 J. R. AlTLloel-g ETAL I $319,387 7 I MINING MACHINE Filed Aug.9,.1940 i 11 INVENTORS. 4 Joan! 1?. 'C'Anruac: BY ARM/N -O. .8 us:7-1.5.

Qw r- ATTORNEYS.

Patented May 18, 1943 MINING MACHINE John R. Cartlidge and Armin o.Bruestle, cincinnati, Ohio, assigncrs to The Cincinnati Mine MachineryCompany, Cincinnati, Ohio, a corporation of Ohio Application August 9,1940, Serial No. 351,996

11 Claims. (Cl. 26233) Our invention relates to mining machines and isparticularly directed to improvements in the mounting means for thecutter bits or teeth employed in a coal cutting chain.

The mining machines to which these bits or teeth are applied are of thattype utilizing an endless chain composed of a series of bit blockslinked together. There is a bit holder fior'carrying the bit itselfwhich'is removably mounted on the bit block and which may be easilyremoved and replaced for the insertion of new bits as soon as the oldones have become dull. A chain of this type and to which this inventionrelates is described in Patent No. 2,039,747 issued in the names ofEdwin P. Stenger and Armin O. Bruestle.

Our invention specifically relates to a bit holder for use with the oldand well known type of bit block having a top surface pierced by anaperture in which the shank of a bit holder is retained by means of aset screw. In this type bit block the bit holder may be reversed so thatthe cutting edge of the bit may be presented in either direction withreference to the line of the chain.

Inasmuch as the bit holder as well as the bit is subject to a tremendouswear in use-it is necessary that it be of extremely rugged constructionand be so configured and arranged that removal and replacement in a darkmine is relatively simple.

It is an object of our invention to provide a bit holder which may ibe.used with the conventional type of bit block. and which holds the bit.ex-

tremely firm while in use and at the same time permits easy removal ofboth the bit holder and the retained bit.

It is a further object of our invention to makea bit holder withreversible parts so the parts may be reversed when worn.

It is a further object of our invention to provide a bit holder whichmay be shimmed after it is worn in order to retain the same efliciencyas a new hit holder.

These and other objects of our invention which will be set forthhereinafter or will be apparent Figure 3 is a plan view of our novel bitholder and its block as shown in Figure 1. V Figure 4 is a perspectiveview of the cradle portion of our bit holder.

Figure 5 is a side elevation of a modification of the cradle for usewith our bit holder.

Figure 6 is a section of Figure 5 taken on the section line 6-6.

Figure 7 is a. side elevation of a shim for us with either the cradleshown in Figure 4 or that shown in Figure 5.

Figure 8 is a side elevation of a of our novel bit holder.

Figure 9 is a side elevation of a bit block carrying our novel type ofbit holder similar to Figure l, but with a shim placed between thecradle and the bit block.

Briefly in the practice of our invention, we provide a bit holder havinga head with a bit receiving aperture and a projecting shank forinsertion into the aperture of the bit block. While the head retains theshank portion of the bit and one. end thereof, the opposite end andcutting surface projects beyond the aperture. The shank of the bitholder projects through and the head thereof modified form lies in acradle which surrounds the shank pOI-,

Referring to the drawing the bit block is indi cated at l with the bitholding aperture 2 and the retaining set screw 3.

Our bit holder has the head 4 with the bit holding aperture 5 cuttherein and a pin 6 for coning our novel type of bit holder with aportion cut away to show the construction. 7

Figure 2 is a section taken along the section line 2-2 of Figure l.

tacting the bit and preventing longitudinal movement in one direction.The lower surface of the head 4 is beveled as at I and terminates in theshank it which projects in the usual manner in the aperture 2 and isretained by the set screw 3.

We provide a cradl ll having two parallel side bars H the inner faces ofwhich are beveled as at I2. The side bars ll terminate in the abutmentl3 at one end and the abutment I4 at the other end. The bit holdingabutment I3 has a cut away portion I 5 so as to closely contact thecutting face It of the bit i! when the holder is in place. l

The dimensions and parts are so configured that that the shank 8 of thebit holder is inserted between the side bars ll until the head 4 slidesin the cradle with its beveled bottom edges 1 withinbut preferably notcontacting the bevel 12- of the side bars I I- of the cradle IEI. Therear face 4a of:

the head 4 abuts against the inner face of the abutment l4 while thenotch l in the bit abutting end I3 abuts against the face iii of the bitII.

By the above construction it is apparent that the bit I! is preventedfrom moving longitudinally to the left (Figure 1) by the inner face ofthe aperture 5 and the pin 6 and is prevented from moving in the otherdirection (to the right) by the abutment I3 where its notch l5 contactsthe cutting face N5 of the bit II. In the drawing we have illustrated abit with the faces having a non-parallel surface as is illustrated inPatent No. 2,039,747 issued May 5, 1936 to E. P. Stenger et al., but wedo not limit ourselves to the specific bit. A bit of similar crosssection with parallel cutting surfaces can likewise be mounted in thesame type of holder and cradle with about equal efiiciency.

In order to change the bit ll end for end after one point has becomedull it is merely necessary to loosen the set screw 3 and to lift theholder a sufficient distance for the heel of the cutting face of the bitto clear abutment 5 on the cradle i0, after which the bit can be readilyremoved from the holder.

7 When it is found desirable to reverse the direction of the cuttingmachine, the chain is caused to travel in the opposite direction. Whenthis is done bit I! is brought into proper position by merely looseningset screw 3 and the whole device comprising the bit, bit holder and thecradle is removed from aperture 2 in bit block I. It may then bereversed and reinserted after first removing the set screw 3 andreinserting it in its opposing hole.

Inasmuch as a great amount of strain is placed on the inner-surface ofthe abutment I4 and on surface I 5 and thus tending to quickly wearthem, we have provided a hole 2a which pierces the abutment M. A shim 2ihaving a stud 22 projecting therefrom as illustrated in Figure 7 may bepositioned against the inner surface of the abutment M with the stud 22inserted in the hole 28. This will take up for wear on the inner face ofthe abutment M and I5 as will be apparent from the drawing.

In the modification of the cradle shown in Figures 5 and 6, the cradlehas two identically formed abutments l3 and 13a. These abutments aresimilar in configuration to the abutment 53 shown in Figure 4 anddescribed above. In thismodification the cradle itself may be reversedin relation to the bit and the bit holder 4., In this instance weprovide a hole in both the abutments i3 and [3a to retain the shimholding plug 22 if it becomes necessary to insert a shim 'due to wear.

In the modification illustrated in Figure 8, the abutting surface of theabutment I4 is inclined as is the rear face 4a of the head i. By thisconstruction a wedging action is created between the head 4 with its bitl'l together with the front and rear surfaces of the abutments i3 and M.Inasmuch as the surface of the shank 8 which contacts the end of the setscrew 3 slopes and thus a pulling tendency on the shank and the head isbrought about, this feature together with the wedging action asdescribed insures the setting of the cradle on the top of the bit blockl and the tight setting of the bit carrying head within the cradle.

' In the event it is desirable to make the bit l'l project further inrelation to the bit block I we may encircle the shank 8 of the bitholder below the cradle and above the surface of the bit block I withshims of varying thickness as shown in Fig. 9.

It is apparent that the aperture 5 of the bit holder as well as theposition of the pin 6 may be differently configured in order to retainbits of different shape. It is also apparent that in the use of shims wemay provide them of different thicknesses so that the amount of wear maybe taken up no matter how little or how great. It is to be understoodthat different forms of our preferred form may be made without departingfrom the spirit of our invention.

Having thus described our invention, what we claim as new and desire tosecured by Letters Patent, is:

1. In combination with a bit, a bit .block, a bit holder having a bitretaining aperture and a shank projecting into the bit block, a separateand removable cradle surrounding a portion of the holder and positionedon the block and under the active cutting point of the bit, said cradlehaving an abutment contacting the cutting face and opposing withdrawalof the bit from the bit holder.

2. In combination with a bit, a :bit block, a bit holder having a bitretaining head and having a shank projecting and retained in the bitblock, a separate and removable cradle surrounding said shank andpositioned between the bit retaining head and the bit block, said cradlehaving an abutment contacting the cutting face and opposing withdrawalof the bit from the bit retaining head, the interior of the cradle andthe bottom of the bit retaining head being beveled so that they slidewithin each other.

3. In combination with a bit, a bit block, a bit holder having a bitretaining aperture and having a shank projecting into the bit block, aseparate and removable cradle surrounding said shank and positionedbetween the head of the bit holder and the bit block, said cradle havingan abutment contacting the cutting face and opposing withdrawal of thebit from the bit holder, said bit holder and said cradle beingreversible in said bit block.

4. In combination with a bit, a bit block, a bit holder having a bitretaining aperture, a shank projecting into the bit block, a cradlesurrounding said shank and positioned between the head of the bit holderand the bit block, said cradle having an abutment contacting the cuttingface and opposing Withdrawal of the bit from the bit holder and a secondabutment contacting the rear of the bit holder.

5. In combination with a bit, a bit block, a bit holder having a bitretaining aperture and a shank projecting into the bit block, a cradlesurrounding said shank and positioned between the head of the bit holderand the bit block, said cradle having an abutment opposing withdrawal ofthe bit from the bit holder and a second abutment contacting the rear'ofthe bit holder, a shim placed between said second abutment and the rearof the bit holder and having a projecting positioning stud journaled inan aperture in said second abutment.

6. In combination with a vbit, a bit block, a bit holder having a bitretaining aperture and a shank projecting into the bit block, a separateand removable cradle surrounding said shank and positioned between thebit holder and the bit block, said cradle having an abutment opposingwithdrawal of the bit from the bit holder and a second identicalabutment contacting the rear of the bit holder so that said cradle maybe reversed in reference to said bit holder and bit block.

7. In combination with a bit, a bit block, a bit holder having a bitretaining aperture and a shank projecting into the bit block, a cradlesurrounding said shank and positioned between the bit holder and the bitblock, said cradle having an abutment opposing withdrawal of the bitfrom the bit holder and a second identical abutment contacting the rearof the bit holder so that said cradle may be reversed in reference tosaid bit holder and bit block and both said abutments having a bitretaining groove.

8. In combination with a bit, a bit block, a bit holder having a bitretaining aperture and a shank projecting into the bitblock, a separateand removable cradle encircling a portion of the bit holder andpositioned between the head of the bit holder and the bit block, saidcradle having an abutment which contacts a portion of the cuttingsurface of a retained bit in the holder and opposes removal of the same.

9. In a mining machine chain, a bit block, a

bit holder having a bit retaining aperture and a shank projecting intothe bit block, a separate and removable cradle encircling a portion ofthe holder, a set screw for holding said holder in place, and a cutterbit in said bit retaining aper ture and projecting angularly therefrombeyond the holder, the cutting face of said bit overlying and abuttingsaid cradle and thereby limiting insertive movement of the bit holderinto the bit block.

10. In combination with a multi-pointed bit having cutting faces lyingin dihedral angles, a bit block, a bit holder having a bit retainingaperture and a shank projecting into the bit block, and a separate andremovable cradle surrounding a portion of the holder and positioned onthe block, and under the active cutting point of the bit, said cradlehaving an abutment engaging the

